Room heater



Aug. 29, 1950 C.M.OSTERHELD ROOM HEATER Filed July 8 1946 INVENTOR. CLARK M. OSTERHELD TTY Patented Aug. 29, 1950 ROOM HEATER Clark M. 'Osterheld, Stoughton, Wis., assignor to McGraw Electric Company, Elgin, 111., a corporation of Delaware Application July '8, 1946, Serial No. 682,033

8 Claims. 1

My invention relates to electric heating units and particularly to room type electric air heaters.

An object of my invention is to provide a novel, relatively simple design of electric air heater.

Another object of my invention is to provide a novel form of construction for a portable room type air heater.

Other objects of my invention will either be apparent from a description of several forms of device embodying my invention or will be set forth in the course of such description and particularly in the appended claims.

In the drawings,

Figure 1 is a view, mainly in perspective with part of the outer casing cut away, of a room-type air heater embodying my invention,

Fig. 2 is a fragmentary view in lateral crosssection, showing another form of electric air heater embodying my invention,

Fig. 3 is a fragmentary view in front elevation showing a resistor and a support therefor, and

Fig. l is a view in lateral section therethrough taken on the line 44 of Fig. 3.

Referring first of all to Fig. 1 of the drawings, I have there illustrated a room-type electric air heater designated generally by numeral i which comprises an outer casing consisting of an intermediate member !3 which is preferably made with a front open, as well as a rear open end, the front end being closed by a relatively thin plate of sheet metal I5, while the rear end portion is covered by a substantially similar plate i1. Sheets t3 and plates and il may be made of aluminum and I preferably provide a plurality of slots L9 in the base of part |3 as well as a plurality of slots IS in the side and top walls of part E3. The end members and H are of substantially dished shape and overhang the ends of sheet IS a short distance. I provide a plurality of rods 2|, 23 and 25 which extend through suitable openings in the end plates [5 and [1, rod 2| being positioned at substantially the middle of plates l5 and I! adjacent the top thereof, while rods 23 and 25 are positioned in the lower corners of the front and rear plates l5 and I1. I provide each of the rods with a cap nut 2! for ornament as well as to hold the front and rear plates I5 and I! in tight engagement with the front and the rear edges of plate |3. The rods 2 I, 23 and 25 may be made of some heatand electric-insulating material such as Micalex or asbestos lumber, or they may be made of some metal such as aluminum.

At the inside of the casing, I provide aresistor member 29 which is preferably made of resistor wire and which is adapted to fit into a member 3! which is of substantially U-shape in lateral section and formed of metal, preferably thin aluminum. The member 3| and the resistor member 29 therewithin are bent around rods 2|, 25 and 23, the intermediate portion 33 of member 3| being in engagement with the outside surface of the rods 2|, 25 and 23. I wish to point out here that the winding of member 3| around the rods progresses helically and that I do not desire to be limited to any specified distance between adjacent turns of member 3|.

The resistor member 29 is provided on its entire outer surface with a coating of an integral, inorganic, heat-conducting, high-temperatureresisting, and electric-insulating material which, in case that an aluminum resistance conductor is used, may be made according to the teachings of Patent No. 1,526,127. However, I may also use resistor wire of a resistance material and use the method of the above identified patent or other similar methods which result in a coating of the above described kinds. The thickness of the coating is on the order of .001".

I preferably provide the inner surface of memher 3! with substantiall the same kind of coating as I provide for resistance conductor 29 and preferably I may provide a coating of this kind over the entire outer surface of member 3! One way of reducing the amount of energy translated into heat in the resistance conductor 29 is by winding the adjacent turns of resistance conductor 29 with a space therebetween, the proper changes being made in the dimensions of the resistance conductor so that the desired wattage will be obtained in the resistance member.

Referring now to Fig. 2 of the drawings, I have there shown a modified form of design embodying my invention in which four rods 35, 31, 39 and 4| are used, which are adapted to be supported by end plates substantially of rectangular contour. In all other details the heater of Fig. 2 is substantially the same as hereinbefore described in connection with Fig. l of the drawings. I wind on the four rods 35, 31, 39 and 4| a resistor supporting member 3| which contains and supports a resistance conductor 29, the adjacent turns of which may be in engagement with each other or which may be spaced apart as hereinbefore described. I provide a plurality of supporting members 43, one at each corner of the heating unit and I preferably make these of a heat-insulating plastic material such as Bakelite suitably secured to the bottom face of plate While I am of the opinion that the provision of an electric-insulating coating, the thickness of which is on the order of .001", is sufficient if provided on the resistor and on the inner surface of supporting member 3 I, I may provide the electric-insulating coating over the entire surface of member 31 and I may make the rods 2|, 23 and 25 of Fig. 1 as well as the rods 35, 31, 39 and 4| of Fig. 2 of aluminum and provide an electric-insulating coating therearound, thus providing a greater amount of electric insulation between points on the resistor and its supporting structure.

I have not shown any design for terminals since any design now used in the art may be used, such as a socket in, say, end plate l5 to which a plug may be connected, the other end of the plug being connectable to a suitable fixture in a room.

Various modifications may be made in the device embodying my invention without departing from the spirit or scope thereof, and all such modifications coming clearly within the scope of the appended claims, shall be considered as part. of my invention.

I claim. as my invention:

1. A room heater comprising a casing, a plurality of spaced rods, extending through and supported by said casing, an elongated metallic resistor supporting member, of substantially U- shape in lateral section, wound around said rods and with its intermediate portion in engagement with said rods and a helically coiled metallic resistor wire lying snug in said supporting memher, the outer surface of said wire having thereon an integral, thin, inorganic, heat-conducting, high-temperature-resisting and electric-insulating coating.

2. A room heater comprising a casing, a plurality of spaced rods extendingv through and supported by said casing, an elongated metallic resistor supporting member, of substantially U- shape in lateral section, wound around said rods and with itsv intermediate portion in engagement with said rods and a helically coiled metallic resister Wire lying snug in said supporting memher, the inner surface of said supporting member and. the outer surface of said resistor wire having thereon an integral, thin, inorganic, heat-conducting, high-temperature-resisting and electric-insulating coating.

3. A room heater as set forth in claim 1 in which the adjacent turns of said resistor wire are in engagement with each other.

4. A room heater as set forth in claim 2 in which the adjacent turns of said resistor wire are in engagement with each other.

5. A space heater comprising a casing, a plurality of spaced rods extending through and supported by said casing, an elongated thin metallic resistor-supporting member of substantially U- shape in lateral section wound around said rods with the open side of the U facing outward, and a resistor member of coiled metallic wire cradled in and fitting snug in said supporting member, one of said members having on the surface that engages the other, an integral, thin, inorganic, heat conducting, high temperature resisting, electric-insulating coating, whereby to provide good heat conduction from the supported part of said wire to the outer face of said U-shaped support.

6. A space heater as set forth in the immediately preceding claim wherein the coated member includes aluminum and the coating includes an oxidation product of aluminum.

7. In combination in an electric space heating unit, an elongated metal. channel, means for supporting said channel with the open side facing outward from said heating unit, a resistor member of coiled metal wire. cradled in said channel and supported thereby whereby a part of each turn of said coiled wire is left unsupported, and a thin layer of electric-insulating material having good thermal conductivity between said channel and coil, said parts fitting together snug to provide good thermal conduction from said wire to the metal of said channel.

8. The combination of claim 7 wherein one of said coil and support includes aluminum and wherein said insulating layer is integral therewith, is inorganic and high-temperature-resisting and includes aluminum oxide.

CLARK M. OSTERHELD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 989,900 Fey Apr. 18, 1911 1,811,440 Shepard June 23, 1931 1,942,057 Gray Jan. 2, 1934 2,153,078 Deuches Apr. 4, 1939 2,163,457 Challet June 20, 1939 2,292,425 Abrahamson Aug. 11, 1942 2,357,906 Osterheld Sept. 12, 1944 

